Dual Tempest Sonotube Questions (1 Viewer)

[Mike Strassburg]

I'll soon be putting together a dual Tempest sonotube powered by a HS500 amp (running at 4ohms). I want to build it along the lines of the Adire Alignment (50% HT & 50% music). I'm looking for tight, accurate, LOUD bass that hits you in the chest. Not as concerned with going REALLY low.

Dan W sent me a basic design, but it vanished along with the rest of my e-mail at work a few months ago. I'm hoping to get some help here so I don't have to bother him again as I know he's VERY busy.

Size is not a real concern as I can go 5-6' high and 24/30" round and hide it in the corner.

I'm also really confused on the "tune" issue as most guys seem to tune for around 16-18hz. If I wanted to tune for say 20hz or higher how would that affect the: max SPL, clarity, etc...

TIA for any help/suggestions.....Mike

 

[Pete Mazz]

If you're not worried about it going really low, and want fast and accurate, why not just build a sealed sub?

Pete

 

[Mike Strassburg]

Pete,

Do sealed subs offer the same potential for max SPL? Any links to dual Tempest sealed subs as I'm sure Sonotube would not be strong enough. TIA...Mike

 

[Gregg Loewen]

Here is a link to where my dual tempest sonotube was discussed / designed. Feel free to post or email me with any questions.
Gregg
http://www.htguide.com/CFBoards/inde...estTimeout=500

 

[Jack Gilvey]

The Adire alignment should work well for, just double the recipe from the Adire site. A Sonotube is more than strong enough. SPL won't be a problem.

How do you plan to wire the Tempests for 4 ohms?

 

[Mike Strassburg]

Good question Jack, after looking at the Adire wiring paper again I see that it can't be done. Guess I'll have to get by with 250 watts per sub...

Greg,

Subs look GREAT. How do they differ in sound, output, etc...???

 

[Jack Gilvey]

Mike,

Ok, I thought you were going with just one voice coil, which I wouldn't recommend in most situations.

If you go with a double Adire alignment, I'd rather have one large port than four small ones. A 6" port has the same area as four 3" ones, but probably will have less losses and compression. Even an 8" is of manageable length in 428 liters tuned to 16Hz. And the 500 watts @ 8ohms of the HS500 will still be enough to get the drivers near Xmax, you'll get near full output.

 

[Pete Mazz]

Mike,
A sealed dual Tempest sub will have plenty of SPL for a large room. My dual sealed Tempest is 16 cu. ft., ~.6 Q, and takes care of my fam rm that's 24 x 18 with a 7' x 6' opening to another area that's 24' x 24' with a 20' vaulted ceiling. If you calibrate the sub to match your mains, then don't worry, the sub will put out plenty of LF. If you want it to overpower you, just jack up the sub level some more.
Pete

 

[Mike Strassburg]

Thanks for the responses.

Here's what Dan W recommended: 24" diameter tube, 72" long. Mount one Tempest and one vent in each end. For the vents, use 6" ID by 20"L pipe.

Double-thick the endcaps (1.5" thick, assuming 3/4" thick stock) from void-free plywood (Baltic birch or marine grade plywood). Should end up with a net 480L, tuned to 17 Hz.

I'm still a little confused on the: ported vs sealed sub debate. Anyone care to list a few pro/con points for each type of sub?

Another thing: don't ALL subs have to be "musical" since almost every movie soundtrack is full of music, whether instrumental, rock, or dance?? While my current sub sounds good during the action sequences, it sometimes sounds muddy during scenes with only music playing. Want to make sure my sonosub plays clean for BOTH. Thanks again...Mike

 

[Jack Gilvey]

Hi Mike,

That alignment looks very impressive if you've got the space. Basically, the ported will give you appreciably more output (~6db, or 4x) in the deep bass for a given input, as it's not limited there by the displacement of the driver, and it's more efficient. There used to be a rather large gulf in sound quality between ported and sealed, but it's nowhere near as wide as it used to be, and that alignment for those Tempests will sound good and "accurate" with any input, whether it be music or explosions. Certainly nothing like the "boom-boxes" that pass themselves off as subs.

Having said that, I doubt you'd be dissappointed with either, as the Tempest works extremely well both ways.

 

[Mike Strassburg]

One more question: Dan W recommended using "void free" Baltic Birch for the end caps (1.5" thick) I've called a few places so far and haven't been able to locate any, only BB hardwood which was 7 ply.

The local HD has 3/4" MDF in stock. How much of a difference will it make if I use MDF for the endcaps? Also I planned on adding another cap top & bottom so total thickness would be 2.25"....if that makes a difference. TIA....Mike

 

[Jack Gilvey]

That would be fine, Mike, you're approaching the properties

of concrete with 2.25" of MDF. Baltic Birch and other no-void plys are more rigid, so you can use less for the same qualities, but they're more expensive and can be a pain to find. Also, sonotubes sometimes benefit from the extra weight of the MDF.

 

[Mike Strassburg]

Thanks for the info Jack.....made my day!!
Trying to scrounge up all the stuff I need while I'm waiting for the parts to arrive from Adire....
The more I anticipate the sound of my sonosub the more I dislike my current sub